1. Field of the Invention
The present invention relates to linear ball bearings of which a bearing member is slidable relative to a guide member in a linear direction. Such bearings are used in various apparatuses such as automated office equipment.
2. Description of the Related Art
Recent improvements in office automation equipment to increase the speed and precision at which the equipment operates are the result of employing linear ball bearings in various sliding portions of the equipment. Accordingly, there has been a demand for a further reduction in the size, weight, price, and noise produced during operation of such linear ball bearings.
A conventional linear ball bearing of the type described above comprises a bearing member in which a plurality of balls are circulatably movable through circulation passages, and a guide member contacting the bearing member through the balls. Each of the circulation passages in turn is comprised of an idly moving portion, a loaded moving portion contacting the guide member and respective transfer portions for communicating the idly moving portion and the loaded moving portion for allowing recirculation of the balls. Accordingly, there has been a problem in that it is difficult to manufacture such complex passages by employing an integral molding process.
For this reason, a conventional bearing has, for example as shown in FIGS. 8(a) and 8(b), a holder d comprised of metal, plastic or any other suitable material in which circulation passages e are formed, a barrel b formed of metal or any other suitable material and a shaft c in this case employed as a guide. The bearing also comprises a means (not shown) for fastening the holder d at a predetermined position within the barrel b.
Such a conventional bearing has a drawback in that the holder d is difficult to manufacture and requires a complex assembly process. These difficulties result in limitations to which the size and production cost of the bearing can be reduced.